The grand polyptych, with the "Madonna of Mercy" at its center, represents one of Piero's few documented works and also one of the first commissions he had in Sansepolcro. The polyptych of the Madonna of Mercy was made between 1445 and 1460, in oil and tempera on panel, and is in the Civic Museum of Sansepolcro. The grandiose polyptych, with the Madonna of Mercy at its center, represents one of Piero's few documented works and also one of the first commissions he had in Sansepolcro . In 1445 the Bitturgense Confraternity of Mercy allotted him the work, which was to adorn the high altar of the church adjacent to the hospital, specifying in the contract that the master was not to avail himself of collaborators and that the work was to be delivered within three years.
The artist, however, due to commitments in various parts of Italy, could not keep to these clauses, and it was only fifteen years later that the work, thanks to the help of a collaborator, identified by Salmi as the Camaldolese miniaturist Giuliano Amidei, could finally be said to be finished. The polyptych consists of five large panels, a predella and eleven small panels distributed in the cymatium and on the sides.
In the center is Our Lady of Mercy, a depiction of the Virgin Mary opening her cloak to give shelter and protection to the people who venerate her, derived from the medieval custom of cloak protection, which high-ranking noblewomen could grant to the persecuted and those in need of help. The worshippers are hierarchically smaller and are arranged in semicircles, four on each side (men on the left and women on the right), leaving an ideal place in the center for the observer. Among them can be seen a hooded confrere, a wealthy notable dressed in red, and, according to a long and plausible tradition, the man turned toward the viewer next to Mary's robe would be a self-portrait of the painter. to note finally that the saints are depicted, we do not know if intentionally, in a chronological order i.e. from youngest to oldest thus highlighting the ages of the man.